The present invention relates to a power operated knife that includes a depth limiting attachment for controlling a thickness of fat covering that is left on a piece of meat.
Power operated knives have been used in commercial meat processing operations to trim fat and connective tissue from meat, trim pieces of meat from bones, and to produce meat slices. Such knives are often constructed so that they are driven via a long flexible drive shaft. The knife operator wields the knife relatively freely at a meat cutting workstation that is remote from the driving motor.
One example of a prior art rotary knife is disclosed in a PCT patent application published on Apr. 12, 2001 under publication number WO 01/24977 A2. This published PCT application is entitled xe2x80x9cPower Operated Rotary Knifexe2x80x9d.
The rotary knife disclosed in this PCT published application has a depth-of-cut controlling gauge whose position can be adjusted relative to the blade. The gauge is detachably connected to a clamp assembly that holds the blade in place so that the gauge may be removed if the operations to be performed by the knife do not require a cut-thickness gauge. The gauge includes an annular gauge unit that comes in contact with the meat that is being sliced to limit the depth to which the rotary blade will enter the meat as the user moves the knife through the meat.
The depth gauge in the above referenced PCT published application is mounted to contact the meat within the inside diameter of the knife blade. The gauge rests on the outer layer of fat or meat. This gauge controls how far the blade will penetrate the surface of the meat thereby controlling how much material is removed from the outside surface of the product. It does not result in the blade following the meat contour underneath a fat layer on the meat.
U.S. Pat. No. 5,484,331 to Buhlke entitled xe2x80x9cMethod and Device for Hot Fat Trimmingxe2x80x9d concerns a trimming knife for retaining a predetermined thickness of fat on a carcass or piece of meat. A guide attached to the knife contacts meat and is capable of compressing fat to the surface of the meat but not into the meat. However, the fat is being compressed therefore the thickness of the fat remaining is dependent on the thickness of the compression.
The present invention provides a new and improved motor driven knife that includes a depth of cut limiting attachment for controlling a thickness of material remaining as a motor driven knife blade is moved over a surface.
One embodiment of the invention includes a motor operated knife having a blade that defines a cutting edge that extends along at least a portion of the blade. A blade support assembly supports the blade for movement as the blade is brought into contact with an exposed surface of a material. A manually grippable handle assembly supports the blade thereby allowing an operator to orient and move the blade to cut material away from the exposed surface. A drive transmission engages the blade for driving said blade during manipulation of the knife. The knife also includes a cut depth-limiting device that is mounted for movement with the handle assembly during manipulation of the knife. The depth-limiting device includes one or more prongs that enter the material during operation of the knife to limit a depth to which the blade enters the material.
Practice of the present invention produces a consistent and uniform thickness of fat coverage on the exterior of a meat cut even if the surface is non-uniform before trimming is commenced. The depth-limiting device penetrates an outer fat cover until the device encounters a membrane between the fat and lean meat. The limiting device holds the knife blade at a predetermined height above this membrane. The limiting device will follow the contour of the membrane allowing the knife to leave a consistent thickness of fat on the meat cut or animal carcass.
An exemplary embodiment of the invention is used in conjunction with a rotary driven knife having a generally circular blade. This knife has special utility for trimming fat from a piece of meat. This use of the invention provides the desired effect of allowing a user to trim fat from recently slaughtered meat while leaving a controlled thickness of fat on the meat.
Additional features and advantages of the invention will become apparent from the following description of a preferred embodiment made with reference to the accompanying drawings, which form part of the specification.